Interaction of ion beams with dusty plasmas

Abstract

The interaction of powder particles, which are confined in the sheath of an asymmetric capacitively coupled rf-plasma, with an external ion beam has been investigated. In contrast to other experiments where particle displacement and oscillations are excited by electric fields or laser radiation, respectively, we excite the particles by additional energetic ions. By this suitable diagnostics, optimization and adjustment of ion beam sources for thrusters or applications in surface treatment can also be provided. By observing the position and movement of the particles in dependence on the discharge parameters we obtained information on the electric field (2.5 × 10 3 V m −1 ) in front of the electrode as well as on the ion drag (1-5 × 10 −14 N).

Behavior of a porous particle in a radiofrequency plasma under pulsed argon ion beam bombardment

“…The experiments are carried out in the PULVA II reactor [15]. It consists of a cylindrical reactor with a diameter of 400 mm (figure 1) and pumped with the help of a 500 l s −1 turbomolecular pump to a residual gas pressure of less than 10 −4 Pa.…”

“…whereas the ion density was obtained from the energy influx of 0.06 J cm −2 s −1 measured by a thermal probe [15,40]. For an ion beam energy e 0 U s = 800 eV, we thus obtain F i = 9.5 × 10 −10 N. We can compare this number with the force F = κ z = 1.6 × 10 −8 N required for a mean particle displacement of z = 4.5 × 10 −4 m during its interaction with the ion beam ( figure 7).…”

“…The interaction of an ion compared to a laser beam offers the advantage that at the same beam power a larger momentum can be transferred to the particle [15]. For that purpose, a particle trapped in the sheath was exposed to a pulsed ion beam with known intensity and energy and was thereby excited to an oscillatory motion.…”

PI3D processing of DLC coatings for different applications

“…Cross sectional SEM revealed nano structure of the films with dimensions close to the roughness value. Although growth mechanism of such films is not clear yet, it is associated with formation of dusty plasma [16]. Surface topology of these films possesses a 'lotus effect' and may be used to form hydrophobic coatings.…”

Microparticles as Plasma Diagnostic Tools

“…Microparticles have already been used for a measurement of the momentum flux in an energetic ion beam ('particles as force probes', [6,7]). In one of our experiments, hollow glass microspheres were injected into the vertically upward directed beam and their trajectories were recorded with a CCD camera.…”